Clamp-washers for hand wheel clutches of sewing machines



Nov. 4, 1958 L. J. KUHAR 2,858,785

CLAMP-WASHERS FOR HAND WHEEL CLUTCHES OF SEWING MACHINES Filed Dec. 2.1954 IN VENTOR I Ludwig J. Kuhar WITNESS ATTO NE Y United States PatentCLAlVlP-WASHERS FOR HAND WHEEL CLUTCHES F SEWING MACHINES Ludwig J.Kuhar, Clark Township, N. J., assignol' to The Singer ManufacturingCompany, Elizabeth, N. J., a corporation of New Jersey ApplicationDecember 2, 1954, Serial No. 472,583

4 Claims. (Cl. 112--220) This invention relates to sewing machines andmore particularly to an improved clamp-washer used as part of the handwheel clutch of a sewing machine.

For many years sewing machines have been equipped with hand wheelclutches by means of which the main shaft of the sewing machine may beconnected to or disconnected from the hand wheel. When the clutch isdisengaged, the hand Wheel may be driven without driving the main shaftof the sewing machine. Because of this a bobbin winder can be drivenfrom the hand wheel or the hand wheel driving belt while other parts ofthe sewing machine remain stationary. One form of a hand wheel clutch isshown in United States Patent No. 1,934,- 373, issued November 7, 1933.

While hand wheel clutches have, for the most part, proved satisfactory,it has been found that the clampwashers heretofore used have, in someinstances, caused difficulty when the clutch parts were engaged ordisengaged. Therefore, one of the primary objects of the presentinvention is to provide an improved clamp-washer especially adapted foruse with the hand wheel clutch of a sewing machine.

Another object of the invention is to provide an improved clamp-washerwhich will flex whenever the hand wheel clutch of the sewing machine isengaged.

Another object of the invention is to provide an improved clamp-washerwhich may be used on any of the individual sewing machines of aparticular class, thereby eliminating the need for selecting aclamp-washer that will work best with a particular sewing machine.

With these and other objects in view as will hereinafter appear, theinvention consists in the devices, combinations and arrangements ofparts hereinafter described in connection with the accompanyingdrawings, which illustrate a preferred embodiment of the invention andin which:

Fig. 1 is a vertical sectional view showing a portion of a sewingmachine and specifically illustrating a hand wheel clutch using animproved clamp-washer which embodies the present invention;

Fig. 2 is an exploded perspective View further illustrating parts shownin Fig. 1;

Fig. 3 is a side elevational view of the clamp-washer shown in Figs. 1and 2;

Fig. 4 is a view similar to Fig. 1 but showing another type of handwheel clutch and clamp-washer embodying the present invention;

Fig. 5 is an exploded perspective view further illustrating parts shownin Fig. 4; and

Fig. 6 is a side elevational view of the clamp-washer shown in Figs. 4and 5.

Many different types of sewing machines may be equipped with a handwheel clutch having a clampwasher of the type herein described, however,the invention illustrated in Figs. 1, 2 and 3 is shown applied to aself-contained motor-driven sewing machine of the type shown in U.S.-Patent No. 1,934,373, supra. The sewing machine illustrated comprisesa number ofelements fully set forth in Patent No. 1,934,373, andincludes a gooseneck or bracket-arm 16 formed with a cylindrical bearingboss 17 adapted rotatably to support a main shaft 18, the bearing boss17 being surrounded by a flat annular surface 19 formed on thebracket-arm 16. Other elements of the sewing machine include a cupshapedmotor frame casting 21, a worm 22, a motor shaft 23 carrying the worm22, a sleeve 24, a hand wheel 26, a gear 27, a circular spring 28, athin metal washer 29 and a collar 30. It will be understood that themotor shaft 23 drives the worm 22 which in turn drives the gear 27. Thegear 27 is, by means of the washer 29 and the spring 28, arranged todrive the hand wheel 26, and by means, presently to be described, thehand wheel 26 selectively drives or is disconnected from the sleeve 24,which in turn drives the main shaft 18. The sleeve 24, which is securedtothe main shaft 18 by means of a tapered pin 31, is provided at one endwith a flange 32, one annular shoulder or surface of which is designatedby the numeral 33. The other end of the sleeve 24 has an end surface 34and an internally threaded bore 36, the surface 34 being interrupted bya pair of diametricallyrecess 47 having an annular clutch surface orseat 48,

the recess 47 being adapted to receive a clutch member or clamp-washer49 presently to be described. A clutch screw 51, having an externallythreaded shank 52 and a boss 53 with an internally facing annular clutchsurface 54, is screwed into the internally threaded bore 36 of thesleeve 24. The screw 51 also has a removable stop pin 56 and in order toprovide for easy manipulation, the rim 57 of the screw 51 is knurled. Inorder to cause the clampwasher 49, which is annular in form, to rotatewith the sleeve 24, the clamp Washer 49 is provided with a pair ofdiametrically opposite inwardly extending keying tongues 58-58 whichenter the keying notches 37-37 of the sleeve 24. The front or outer face59 of the clamp-washer 49 has three outwardly struck lugs 6161-61, eachlug having an outwardly facing sur- 7 face 62 designed to engage theclutch surface 54 of the screw 51. Also protruding from the outersurface 59 of the clamp-washer 49 are three equidistantly spacedstop-pins 63-6363, these pins in certain circumstances being engaged ina known manner by the stop-pin 56.

The inner or rear surface 69 of the washer 49 has three struck lugs71--7171, each providing an iufacing surface 72 arranged to engage theannular clutch seat '48 of the recess 47. Reference to Fig. 2 shows thateach lug 71 is spaced equidistantly between a pair of lugs 61-61,- andthat each lug 61 is spaced equidistantly between a pair of lugs 71-71'.In other words, the

lugs 61 and 71 are alternately arranged or circumferentially spacedaround the washer 49 so that lugs 61 are spaced sixty degrees (60) fromlugs 71 and so that g each lug 61 is spaced one hundred-twenty degreesfrom each of the other lugs 61, also so that each lug 71 is spaced onehundred-twenty degrees (120") from It will also be noted (Fig. 2)

51 is tightened in the threaded bore 36 of the sleeve 24,

the clutch surface 54 of said screw engages the three equally spacedsurfaces 62-62-62 on one side of the clamp-washer 49, while the threesurfaces 72-72-72 onthe opposite side of the clamp-washer engage theannular clutch seat 48 on the hand wheel 26. Since the surfaces 62-62-62are circumferentially spaced about the clamp-washer relatively to thesurfaces 72-72-72, the washer flexes slightly as the clamp screw 51 istightened. The flexing of the clamp-washer permits the clutch screw 51to be readily tightened effectively to lock the hand wheel to thearm-shaft and at the same timeit permits the clutch screw to be loosenedwith the application of only a small amount of effort on the part of theoperator. It will be further appreciated that the surfaces 62-62-62 and72-72-72 provide in effect three-point contact between the clutch faceon the hand wheel and the clutch. face on the clamp screw with theobvious advantage that, regardless of the looseness of fit between thethreaded shank 52 and the threaded bore- 36, the clamp screw will seatsquare with the clutch face 48 on the hand wheel and consequently willrun true with the hand wheel.

Figs. 4, and 6 disclose a modified form of the invention as applied to abelt driven sewing machine having among other elements a bracket arm 116provided with a bearing bushing 117 adapted rotatably to support a mainshaft 118. Other elements of the sewing machine include a belt 125 fordriving a hand wheel 126. A cylindrical sleeve 124, which is secured tothe main shaft 118 by means of a screw headed pin 131, is provided atone end with a flange 132, one annular surface of which is designated bythe numeral 133. The other endof thesleeve 124 has an end surface 134and an internally threaded bore 136, the surface 134 being interruptedby a pair of diametrically opposed keying notches 137-137. The handwheel 126 is formed with an annular end face 146, which abuts theaforementioned annular surface 133. The outer face of the hand wheel 126is provided with a collar 147 having an annular clutch face 148, theface 148 being adapted to be contacted by portions of a clamp-washer149, presently to be described. A clutch screw 151, having an externallythreaded shank 152 and an internally facing annular clutch surface 154is screwed into the threaded bore 136. The screw 151 has a removablestop pin 156 and a knurled rim 157 of known construction.

In order to cause the washer 149 to rotate with the sleeve 124, theclamp-washer 149 is provided with a pair of diametrically opposedinwardly extending bent key tongues 158-158, which enter the notches137-137, one of the key tongues being bent toward the front face of. theclutch member and the other key tongue being bent toward the rear faceof the clutch member, as shown. in Fig. 5, so that the clutch member canbe placed on the shaft with either face being considered the front face.The outer rimof the washer 149 is substantially annular in form exceptfor the fact that this rim has three outwardly extending lugs163-163-163 which, in certain circumstances, are engaged in a knownmanner by the stop-pin 156. The front or outer face 159 of theclamp-washer 149 has three outwardly struck lugs 161-161-161, each lughaving an outwardly facing surface 162 designed to engage the clutchsurface 154. The inner surface 169' of the Washer 149 has three struck.lugs 171-171-171 each providing an infacing surface 172 arranged toengage the annular clutch face 148. This arrangement of lugs provides awasher 149 which could be said to be corrugated. The lugs 161 and 171are spaced around the washer 149 ,in the same manner as the lugs 61 and71 are spaced around the washer 49-, the only difference being that thelugs 161 and 171 both extend from the inner circumference tothe' outercircumference of the washer 149. The clampwasher 149 functions. in. thesame manner as that previously described for the washer 49.

Having thus set forth the nature of the invention, what I claim hereinis:

1. A sewing machine comprising a main shaft; a sleeve carried by saidshaft and thereby forming a shaft-sleeve combination, one end of saidshaft-sleeve combination being provided with a threaded portion and akeying notch; a hand wheel mounted on said shaft-sleeve combination,said hand wheel having on a front portion thereof a surface located in aplane normal to the axis of said shaft; means for driving said handwheel; a threaded clamp means engaging the threaded portion of saidshaft-sleeve combination and having an annular surface located in aplane normal to the axis of said shaft on said threaded clamp means; astop lug carried by said threaded clamp means; and an annular clampwasher adapted to be interposed between the surface on the front portionof said hand wheel and-the annular surface on said threaded clamp means,said clamp washer comprising a front face, a rear face, an innercircumferential surface, a keying tongue extending radially inwardlyfrom said inner circumferential surface and engaging said keying notch,three lugs protruding axially from the rear face of said clamp washerand having infacing surfaces adapted to engage the surface on the frontportion of said hand wheel, three lugs protruding axially from the frontface of said clamp Washer and having outfacing surfaces adapted to beengaged by the annular surface on said threaded clamp means, said lastnamed three lugs extending radially from this innercircumferentialsurface to a maximum radial distance defined by a circle concentric withsaid inner circumferential surface, and a plurality of stop-memberscarried by said clamp-washer and adapted to contact said stop-lug onsaid threaded clamp means, said stop-member being located radiallyoutside of said last defined circle. 7

2. A sewing machine including a frame, a shaft journaled in-said frameand having fixed thereto a first member providing an annular shouldernormal to the axis of said shaft, a hand-wheel supported by said shaftto turn about the axis of said shaft and having an: inner hub facearranged to bear against the annular shoulder of said first member, saidhand-wheel having an outer hub face located in a plane normal to theaxis of said shaft; a clamp member threadedly supported by said shaftand having an annular surface located in a plane normal to the axis ofsaid shaft, and an annular bodied clutch member apertured to receivesaid shaft and interposed between the outer hub face on said hand-wheeland the annular surface on said clamp member, said clutch member havinga front face and a rear face, three lugs protruding axially from therear face of said clutch member and having intacing surfaces adapted toengage the outer hub face of the hand-wheel, and three lugs protrudingaxially from the front face of said clutch member and having outfacingsurfaces adapted to be engaged by the annular surface on said clampmember.

3. A clutch member adapted to be used with a sewing machine having arotary shaft driven by a driving wheel arranged through said clutchmember to be clutched to and declutched from said shaft; said clutchmember com prising an integral annular body apertured to engage theshaft of the sewing machine and having front and rear faces, three lugssubstantially equally spaced around the said clutch member protrudinsaxially from the rear face of said clutch member and having infacingsurfaces defining a plane, and three lugs substantially equally spacedaround the said clutch member pro ruding axially from the front face ofsaid clutch member, and alternately disposedcircumferentially withrespect to the lugs on the rear face and having outfacing. surfacesdefining a plane parallel to that defined by the infacing of said otherthree lugs, each of said lugs having a portion located adjacent to thesurface defining the aperture of said clutch member.

4; A clutch member adapted to be used with a sewing machine having arotary shaft provided with a keying notch and driven by a driving wheelarranged through said clutch member to be clutched to and declutchedfrom said shaft by means of a thumb nut member threadedly supported bysaid shaft; said clutch member comprising an annular body having frontand rear faces and an inner circumferential surface defining a centrallylocated shaft receiving aperture, three lugs protruding axially from therear face of said clutch member and having infacing surfaces defining aplane, three lugs protruding axially from the front face of said clutchmember and having outfacing surfaces defining a plane parallel to thatdefined by the infacing surfaces of said other three lugs, each of saidlugs having a portion located adjacent to said inner cir cumferentialsurface of said clutch member, a pair of diametrically located keyingtongues extending radially inwardly from said inner circumferentialsurface and adapted to enter the keying notch in said rotary shaft, oneof said keying tongues being bent toward the front face of said'clutchmember and the otherof said keying tongues being bent toward said rearface of said clutch member, and stop means provided on said clutchmember and adapted to limit the turning of said thumb nut member.

References Cited in the file of this patent UNITED STATES PATENTS1,934,373 Peets Nov. 7, 1933 2,012,032 Zinnbauer Aug. 20, 1935 2,069,402-Cow1in Feb. 2, 1937 2,097,710 Whitelaw et a1. Nov. 2, 1937 FOREIGNPATENTS 308,309 Italy June 1, 1933 314,425 Italy June 26, 1934 578,289Great Britain June 21, 1946 691,317 Great Britain May 13, 1953

